Because of the wide light spread of the diffused housing, the SHO came from the factory with the 3357K form Sylvania. Previous owner may have been out there replacing them with 3157 - just because 3357K is hard to get a hold of. NAPA, PepBoys, Advance Auto and Canadian Tire do not carry 3357K. Here is an overview over the braking light portion of the taillights. The SHO needs four of them, 2 on each side. The last one is of course the preferrable one.
|Bulb name||Power||Increased light||Available from|
|3157 (stock bulb)||26.8 W||0% (reference)||Evrywhere|
|3357K (K=Krypton gas filled)||28.5 W||66%||Sylvania (sold at Ford dealer)|